Spatiotemporal Variations of Maternal Exposures to Air Pollution and Risks of Adverse Birth Outcomes in Lanzhou, China

摘要

Previous studies indicated associations between air pollution and adverse birth outcomes, but results were inconclusive. Different exposure assessment methods might contribute to this apparent inconsistency. The objective of this study is to estimate maternal exposures to air pollution using exposure assessment methods with various spatiotemporal resolutions, and related risks of adverse birth outcomes in Lanzhou, China. The study population is 8087 singleton live births with maternal and work addresses in Lanzhou urban area. Exposures during entire pregnancy were estimated for PM10, PM2.5 and N02, using land use regression (LUR) models or government monitoring data. Spatial exposure variables were developed: road densities, industrial areas near residence and proximity to major point sources. Logistic or linear regression models were used to investigate associations of maternal exposures with risks of congenital heart defect (CHD), preterm birth (PTB), low birth weight (LBW), or change in birth weight. Models were adjusted for maternal social economic status and risk factors. Risks were estimated for interquartile range increases of exposure variables. Clusters of adverse birth outcomes occurred in the west of the city, where major point sources were concentrated. Maternal exposures to PM10 were significantly associated with increased CHD risks (OR: 2.23, 95% CI: 1.38, 3.58) and reduced birth weight (-21.1 g, 95% CI: -38.5, -3.6 g). Proximity to major point sources marginally elevated LBW risks (OR: 0.82, 95% CI: 0.67,1.00). Effect estimates based on LUR-modeled exposures were more certain than those based on government monitors. Maternal exposures to particles were associated with increased risks of adverse birth outcomes in Lanzhou, which has major point sources. Studies investigating air pollution exposures and related health risks at high spatiotemporal resolutions is valuable for disentangling health effects of different air pollutants or pollution sources.